Electrical cable having an inner conductor, an intermediate primary shield braid and a secondary or outer shield braid has been in commercial use and known as triaxial cable; the inner conductor is surrounded by a dielectric insulation of controlled thickness so that the intermediate shield braid is coaxial therearound, and another dielectric insulation layer surrounds the intermediate shield and in turn is surrounded by the outer shield braid around which is an outer jacket. The primary or intermediate shield is utilized as a ground for the particular article to which the inner conductor is electrically connected; the secondary or outer shield serves as chassis ground and is connected to the outer conductive housing of the apparatus in which the article is mounted such as a computer or an aircraft fuselage. Triaxial cable is commonly utilized to conduct radiofrequency signals at 20 megaHertz with a nominal impedance of 75 ohms, such as for transmission of video signals.
Electrical connectors are known which are used to terminate triaxial cables, and comprise an inner contact, an intermediate ground coaxially around the inner contact and insulated therefrom, and an outer conductor coaxially around the intermediate ground. An example of such a connector is sold by AMP Incorporated, Harrisburg, Pa. under Part No. 222191-1. For many applications at least the mating interface of such connectors is controlled by Specifications such as Military Specification MIL-C-39029/95 and /96 (for "Size 8") and MIL-C-81659 Series 2 (for "Size 5").
Many such connectors have been installed in apparatus over the years and remain useful. It has become desirable to provide for protection of the signals along the circuits in which the connectors have been installed, against electromagnetic pulse (EMP) or electrostatic discharge (ESD), while retaining the already installed connectors in service in a retrofit program. One particular problem has been to provide a package of discrete signal line filters of severely limited dimensions at the mating interface of such in-service connectors with circuit boards or with mating connectors, such as in black boxes in electronics bays of aircraft where almost all space has already been utilized by necessary components. Therefore, any dimension of any element added between the electrical connectors at input/output ports of black boxes to circuit boards therewithin must be kept minimal, for example. Any such filter package retrofitted into black boxes of conventional design must also be removable and replaceable, and compatible with connectors of wiring harnesses already installed in apparatus such as aircraft.
It is desired to provide an interconnecting element for a triaxial connector to a corresponding triaxial connector which maintains the signal integrity and has as short an axial dimension as possible. It is desired to provide such an interconnecting element which is matable with and unmatable from the triaxial connectors after installation for the mating interface of an overall assembly containing one of the triaxial connectors to be separable from the assembly containing the adapter and the other triaxial connector.